Persistent Cold Start Issue MF1560

[Harry in Ky]

To ensure that the starter has the grunt to start the engine in cold weather could you do an experiment where you disconnect anything connected to the pto.
The fact that you only get 2 or 3 revolutions even with something on the pto and turning seems puzzling.
I appreciate you had the starter rebuilt.
Have you ever considered buying an infrared temp measuring gun from Princess Auto for $25
Infrared Thermometer | Princess Auto
This would allow you to easily confirm the glow plugs are getting hot.
While the plugs are new perhaps there are problems in the circuit powering them up.
Put some of the hydraulic fluid in a glass container and put it in the freezer to see how stiff it gets. You did not mention the specifics of the fluid you used.
Dave M7040

I suppose the fluid spec/condition may be of some concern, as this would be the only connection to the problem at hand that's accessible with no dis assembly required. There is nothing electrical involved, so testing any circuits or electrical components will gain you nothing. What you need to find out is WHY does the PTO shaft turn while the engine is cranking? That's the heart of the matter.